Boulder, Colorado 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

238
FXUS65 KBOU 282319
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
419 PM MST Fri Nov 28 2025

.KEY MESSAGES...

- Coldest air of the season arriving Saturday through Monday
  morning.

- Several inches of snow expected in our mountains tonight,
  impacting travel across all passes. Light flurries possible
  (~60% chance) for the lower elevations (little/no accumulation).

- Another round of light to moderate mountain snow expected
  Sunday/Sunday night. Fleeting chance for light snow (~30%) for
  the lower elevations again.

- Slightly milder and mostly dry Monday/Tuesday. Then another
  potential shot at wintry precipitation Wednesday into Thursday.

&&

.DISCUSSION /Through Friday/...
Issued at 1234 PM MST Fri Nov 28 2025

Radar is showing the first few signs of elevated showers
developing upstream over the high country north of I-70, although
water vapor imagery looks rather lackluster thus far. Nonetheless,
light snow showers will gradually increase in frequency over our
northern mountains we enter our evening hours in particular, with
the bulk of the snow from this upcoming system anticipated to fall
overnight into early Saturday morning. The story impact-wise will
remain focused over our high country, where a relatively
widespread 3-6" of snow is expected to create hazardous travel
conditions across the majority of our mountain passes into the
morning hours. Locally favored west-facing slopes in our northern
mountains (mainly north of I-70) may approach 8".

Meanwhile, the lower elevations will be grasping at straws to see
any accumulating snow whatsoever, as has seemingly been the case
throughout the fall. There are two windows of opportunity for
light showers; the first will be late this evening as the left
exit region of the fast-moving jet streak zips overhead, and mid-
level moisture spills east of the Continental Divide. If (and it`s
a fairly large "if") any showers do develop, they`d more likely
bring a wintry mix, with near zero potential for snow accumulation.
Following that, the second window arrives in tandem with the cold
front, still slated for the early morning hours. Potential for
showers appears marginally higher then (closer to 60% chance), and
would certainly be in the form of snow with a sharp frontal
temperature drop, but we will be hard-pressed to squeeze out much
more than a dusting to half inch of snow if those materialize,
with ~1" still being close to the absolute maximum (and certainly
not widespread). The trend, per usual, is not in favor of snow.
Although a few localized slick spots may be found early morning,
the morning commute should be largely unaffected for most urban
corridor locations. So the ultimate question: Will Denver break
its snowless fall streak tonight? It`s genuinely a coin toss.

What the front will be lacking in moisture, it will make up for in
winter-like temperatures, and Saturday`s highs will be
approximately 30 degrees colder than today`s, remaining near or
slightly below freezing for the plains and I-25 corridor.
Overnight temperatures will fall to their lowest values so far
this season, registering in the single digits and low teens for
mountain and plains communities respectively.

The cold airmass will stick around for a little while as we see a
second, more tilted trough dig south over Colorado. Despite its
more amplified nature, the spatial pattern in accumulating
precipitation looks quite similar to the first system - light to
locally moderate snow accumulations in the mountains (generally
less than that received tonight) Sunday and Sunday night, with an
increasingly unimpressive chance (~30-40%) for light snow showers
spilling into the lower elevations. Perhaps the best potential for
minor accumulations outside of the mountains would be for the
Palmer Divide where there will be a slightly more favorable weak
upslope component, but the latest ensembles are not overly excited
for the measurable snow potential elsewhere. Regardless, we`ll
hold on to cold temperatures hovering right around the freezing
mark during the day, and returning into the teens or even a few
single digits Sunday night.

The Monday into Tuesday timeframe will be characterized by gradual
warming (slight on Monday, more substantial for Tuesday) and
generally dry conditions, outside of a small chance (~25%) of a
few mountain showers showers later Tuesday ahead of another
potential troughing pattern. It`s worth noting that there is
little agreement in the progression of the upper-level early to
mid-week, with some guidance signaling a more progressive
shortwave with varying tracks, and others favoring development of
a closed or cutoff low over California. Ensemble mean solutions
are thus the best way to go at this time, which would favor a
return to cooler and potentially "wetter" conditions (please note
the inclusion of quotation marks here) for Wednesday and perhaps
into Thursday. Approximately 70-80% of members carry snowfall
accumulations into our mountains for mid-week, with that
proportion falling to around 50% for our lower elevations.

&&

.AVIATION /00Z TAFS through 00Z Sunday/...
Issued at 410 PM MST Fri Nov 28 2025

Winds will be mainly light and variable this evening before cold
front moves across between 08z and 09z. Winds behind the front
will be gusty from the NNE up to 35 mph. These winds will
gradually decrease by 13z and become more ENE. By 17Z winds will
become NNE again with a few gusts up to 25 mph at DIA.

Meanwhile there will be a chc of rain showers possibly mixed with
some snow between 04z and 08z. After frontal passage there will
be a brief window of light snow/flurries between 09z and 13z.
Ceilings will be MVFR after 08z and may linger thru 16z or 17z.
After 17z will see VFR conditions develop.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 8 AM MST Saturday for COZ031-033-
034.

&&

$$

DISCUSSION...BRQ
AVIATION...RPK